Speedometer.



A. A. CANTON.

SPEEDOMETER.

APPLICATION FILED IuLY I. 1914.

price.

ALLEN A. CANTON, OF NEW YORK, N. Y.,"AssIcNoIt To THE DEVICE TESTINGCOMPANY, A CORPORATION OF CONNECTICUT.

SPEEDOMETER.

Specification of Iietters Yatent.

Patented May 1, 1917..

To all lwhom t may concern: l

Be it known that I, ALLEN A. CANTON, a citizen of the United States ofAmerica, and a resident of the'c'ity, county, and State of New York,have invented certain new and useful Improvements in Speedometers, ofwhich the following is a specification.

This invention relates to speedometers. The object of the invention isto provide a speedometer adapted to be made small and compact and at thesame time of great eiliciency, comprising but a few parts so that it maybe manufactured and sold at a low Another Object of the invention is toimprove thc` construction of speedometers generally with,a view ofgreater eiiiciency and greater range of usefulness. NVith these andother objects in view the invention comprises a speedometer asillustrated in the accompanying drawing and described in the followingspecification. In the drawttligure 1 is a front elevation of thespeedometer.

Fig. 2 'is a side View with the casing in section.

Fig. 3 is atop view, and

Fig. 4 is a wiring diagram.

The reference numeral 5 denotes a casing of suitable size andl formadapted to contain and support the various parts of the instrument. Thefront portion o is preferably semi-circular in form and bears a scale 7.8 is a slot in the front portion 6 through which' projects the indicatoror pointer 9 which indicates on the scale the speed of the movableelement, as for instance the shaft- 10 in Fig. 5 which it is desired tomeasure.

The pointer 9 is secured to an iron spindle 11 which is pivoted in aframe 12 secured in the casing by screws or otherwise. 13 is a bearingscrew for regulating the friction between the spindle and the frame.

The pointer 9 is secured to 'the spindle 11 in prolongation of a radialarm 14. by means oQflwhch arm a circular magnet 15 is also secured tothe spindle. The poles'16 and "1V of the magnet 15 are disposed anequal'l distance from the pointer 9 as shown. To the bottom of thespindle there is secured a soft iron disk 18.

The spindle 11 forms 'the core of an electro-magnet the coil of which ismarked 19.

The lspindle is free to move within the coil,

which is mounted between two supports 20 secured to the t'rame 1L). Thecoil 19, when current is sent through it` serves to magnetize the.spindle 11, and thereby increase the strength of the magnet 15. The disk18 is for the purpose ot' lowering the reluetance of the magneticcircuit from the magnet 15 when the coil 19 is energized.

The spindle l1 and with it the pointer 9 are operated b v two solenoids21 and 22 mounted upon the upper support 20 and ivhich solenoids arehollow so as to permit the magnet `15 to pass` through them andoscillate with the spindle 11.- The solenoids are wound in such a mannerthat they have a tendency to repel the poles 16 and 1T of `"solenoid Q1with respect to the solenoid Q2, or the resistance may be omitted andthe solenoid 2; be provided with a greaternumber ot'V ampere turns, it'desired.

The solenoid '29. is connected across the battery and in series with amagnetic `interruptor :'26 comprising a toothed magnetized disk :27,secured to the shaft 10, the

speed ot which is to be measured, and an oscillating armature QS whichis magnetized with a magnetism of a polarity opposite'to that of thedisk Q7. When the shaftV l10 is' at rest. the solenoid is shortcircuitedb v way of the interrupter and the circuit 29 and 30. :il is aresistance to prevent shorten-uniting ot' the battery as will beunderstood. 1,/

lt follows, that the coil 19 and the solenoid .21 are always charged andas a consequence the solenoid Q1 repels the pole 16. of the magnet asshown and moves the pointer 9-into zero position.

When the shaft 10 commences to rotate,- Athe armature 28 is oscillatedwhich momentarily interrupts the circuit 29-30 and permits a currentimpulse to pass throughfthe solenoid 22. The faster the shaft 10rotatesf the faster the current impulses pass through titi Mill

Solenoid 22, 'thereinv building up the nnignetisni of the lutter inproportion to die the pointer is moved back to zero position by thesolenoid 21. repelling 4tlie polo 3 6 oi i the magnet. The movements ofthe pointer nre limited by the siot 8.

From the itoregoin it will be seen tliet have provided e smo lefi'icient speedometer which operates with greet :tccurocy because theindicotinI means, that is the pointer as fixed with re ation to themagnet i5, is operated in response to the frequency or' the currentimpulses only, which nre in direct proportion to the speed of the shafti0. This instrument possesses e further adventoge in that a. variationin tire voltage does not affect its accuracy because both solcnoids areequallyy attested.

i llore found tliis 4instrunient to Werl; ce curutely in actualpractice, and that it works better with than Without tiic coil. i9.Changes in the detnfi'ed construction muy loe made 'without departingfrom tire principle of the invention on the scope of the op pendedclaims l. A speedometer comprising-g :i pair of solenoids of differentmagnetic strength, o. magnet mounted to movcin response to the seiddifference of inngnetie strength, n spindle upon which the said magnetsupported, coil of wire around said spindle and menne for supplyingcurrent to the latter and the said two solenoids.

n. it speedometer comprising a pair of Solenoids of diilerent magneticstrenogtli, e magnet mounted to move in response to the seidditli'erenco of magnetic strength, e spindle upon-luiden the saidinngnct is supportvd. a source nl electric energy, connections betweenthe latter :1nd the said two solenoids und a coil ot' wire surroundingthe said spindie and connected in series with one of the said coils.

3. A speedometer comprising n pair of solenoids of dil'ercnt; magneticstrength, a magnet mounted to more in response to the said diiicrencc ofmagnetic strength, n spindle upon which the seid nnignet is supported, acoil ot' wire around said spindle, means tor supplying n constantelectric current to the said coil of wire und the one solenoid, andmeans i'oi' supplying :in intermittent currentto the other solenoid.

i. It spinnlomcter comprising n mombly mounted magnet, n, pair ofsolenoids for op erating seid magnet. means for indicating,r themovement of ille latter, moruble supporting ineens i-or seid nlairnet,a` coil of wire surroundineA said supporting ineens and moons forsupplying' current to the said coil of wire and the said solenoids.

ii. speedometer comprising a pair of solenoids o'l" dili'erent inngneticstrength, a magnet nnninted to morewithin said solcnoids and in responseto their different mag` netic strength, a source of electric energy,connections between the latter and the Suid solenoids undelectro-magnetic ineens for streinftiiening the magnetism in said magnetund connected to tire said source oi energy.

(i. A speedometer comprising s casing, a hollowl coil .of wire supportedin the sume, a spindle inovabiy supported Within Suid coil, e magnetsecured to scid spindle at the one end thereof, a soft iron disk securedto the spindle nt the opposite end, a pair of Soienoids supported iniixed relation to said muguet and surrounding the same, a pointersecured to said spindle to indicate the movenient of the sind magnet endIneens for iimiting the movements or' the pointer.

Signed :it New York, N. Y., this 30th day of June, 1914:.

lum liionlosrsnno, 4 it. G. Lutin.

